Composition for etching and manufacturing method of semiconductor device using the same

ABSTRACT

The present invention relates to a composition for etching, comprising a first inorganic acid, a first additive represented by Chemical Formula 1, and a solvent. 
     The composition for etching is a high-selectivity composition that can selectively remove a nitride film while minimizing the etch rate of an oxide film, and which does not have problems such as particle generation, which adversely affect the device characteristics.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation application of U.S. patent applicationSer. No. 16/228,780, entitled “Composition for Etching and ManufacturingMethod of Semiconductor Device Using the Same”, filed on Dec. 21, 2018,which claims priority under 35 U.S.C. § 119 to Korean Patent ApplicationNo. 10-2016-0178754, filed on Dec. 26, 2016, Korean Patent ApplicationNo. 10-2016-0178757, filed on Dec. 26, 2016, Korean Patent ApplicationNo. 10-2017-0178590, filed on Dec. 22, 2017, and Korean PatentApplication No. 10-2017-0178591, filed on Dec. 22, 2017, in the KoreanIntellectual Property Office, the disclosures of which are incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a composition for etching, and moreparticularly, to a high-selectivity composition for etching capable ofselectively removing a nitride film while minimizing the etching ratefor an oxide film, and to a method of manufacturing a semiconductordevice, the method including an etching process employing the etchingcomposition.

BACKGROUND

In semiconductor manufacturing processes, representative insulatingfilms include oxide films such as a silicon oxide film (SiO₂), and thelike, and nitride films such as a silicon nitride film (SiN_(x)), andthe like, which are used each independently, or in one or morealternately stacked layers. Further, these oxide and nitride films arealso used as hard masks for forming electroconductive patterns such asmetal wiring, and the like.

In a wet etching process for removing a nitride film, a mixture ofphosphoric acid and deionized water is generally used. The deionizedwater is added in order to prevent a decrease in the etch rate and avariation in the etch selectivity for oxide films; however, there is aproblem in that even a small change in the amount of deionized watersupplied may cause defects in the process for removing a nitride film byetching. Furthermore, phosphoric acid is a strongly corrosive acid, andhandling of this acid is difficult.

In order to solve these problems, technologies for removing nitridefilms using a composition for etching employing phosphoric acid (H₃PO₄)together with hydrofluoric acid (HF) or nitric acid (HNO 3) have beenconventionally reported; however, these technologies have ratherresulted in lowering of the etch selectivity between nitride films andoxide films. Further, technologies implementing a composition foretching including phosphoric acid and a silicic acid salt or silicicacid are also known, but these have a problem in that silicic acid or asilicic acid salt causes generation of particles that may adverselyaffect a substrate, and they are therefore rather unsuitable for thesemiconductor manufacturing processes.

FIG. 1 and FIG. 2 are process cross-sectional views illustrating adevice separation process for a flash memory device.

First, as illustrated in FIG. 1, a tunnel oxide film 11, polysiliconfilm 12, buffer oxide film 13, and pad nitride film 14 are sequentiallyformed on substrate 10, and then the polysilicon film 12, buffer oxidefilm 13, and pad nitride film are selectively etched to form trenches.Subsequently, spin-on-dielectric (SOD) oxide film 15 is formed until thetrenches are gap-filled, and then the SOD oxide film 15 is subjected toa chemical mechanical polishing (CMP) process using the pad nitride film(14) as a polishing stopper film.

Next, as illustrated in FIG. 2, the pad nitride film 14 is removed bywet etching using a phosphoric acid solution, and then the buffer oxidefilm 13 is removed by a washing process. Thereby, a device separationfilm 15A is formed in the field region. However, in the case of usingphosphoric acid in such a wet etching process for removing a nitridefilm, due to a decrease in the etch selectivity between the nitride filmand the oxide film, the nitride film as well as the SOD oxide film areetched, and thus, it becomes difficult to regulate the effective fieldoxide height (EFH). Accordingly, a sufficient wet etching time forremoving the nitride film cannot be secured, or additional processes areneeded, and thus phosphoric acid causes changes which adversely affectthe device characteristics.

Therefore, under the current circumstances, there is a demand for ahigh-selectivity composition for etching that can selectively etch anitride film with respect to an oxide film in a semiconductor productionprocess, but which does not have problems such as particle generation.

SUMMARY

An object of the present invention is to provide a high-selectivitycomposition for etching that can selectively remove a nitride film whileminimizing the etch rate of an oxide film, and which does not experienceproblems, such as particle generation, adversely affecting the devicecharacteristics, and a method of manufacturing a semiconductor deviceusing the same.

An embodiment of the present invention provides a composition foretching, comprising a first inorganic acid, a first additive representedby Chemical Formula 1, and a solvent.

In Chemical Formula 1, X may be O or N; R1 to R6 may be eachindependently selected from the group consisting of hydrogen, a C1-C20alkyl group, a C1-C20 alkoxy group, a C2-C20 alkenyl group, a C3-C20cycloalkyl group, a C1-C20 aminoalkyl group, a C6-C20 aryl group, aC1-C20 alkyl carbonyl group, a C1-C20 alkyl carbonyloxy group, and aC1-C10 cyano alkyl group; n11 may be 0 or 1; and at least two of R1 toR4 may be C1-C20 alkoxy groups when n11 is 0.

The first inorganic acid may be one selected from the group consistingof sulfuric acid, nitric acid, phosphoric acid, silicic acid,hydrofluoric acid, boric acid, hydrochloric acid, perchloric acid, andmixtures thereof.

The composition for etching may include 0.01 to 15 wt % of the firstadditive and 70 to 99 wt % of the first inorganic acid, with theremaining amount as solvent.

The composition for etching may further comprise a second additive,including a silane inorganic acid salt produced by reacting a secondinorganic acid with a silane compound.

The composition for etching may include 0.01 to 15 wt % of the secondadditive with respect to the total amount of the composition foretching.

According to another embodiment, the present invention provides a methodof manufacturing a semiconductor device, comprising an etching processperformed using the composition for etching.

The etching process may selectively etch for a nitride film with respectto an oxide film, and the etching process of the nitride film may beperformed at a temperature of 50 to 300° C.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 are process cross-sectional views illustrating adevice separation process for a flash memory device according toconventional technologies.

FIG. 3, FIG. 4, and FIG. 5 are process cross-sectional views forexplaining a device separation process for a flash memory device,including an etching process employing a composition for etchingaccording to an embodiment of the present invention.

FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. 10, and FIG. 11 are processcross-sectional views for explaining a pipe channel forming process fora flash memory device, including an etching process employing acomposition for etching according to an embodiment of the presentinvention.

FIG. 12 and FIG. 13 are process cross-sectional views for explaining adiode forming process for a phase change memory, including an etchingprocess employing a composition for etching according to anotherembodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, a composition for etching according to the presentinvention and a method for manufacturing a semiconductor using the sameis described in detail. The present invention may be subjected tovarious modifications and may include various embodiments, and thusparticular embodiments will be described in detail in the detaileddescription of the invention. However, these embodiments are exemplaryonly and are not intended to limit the scope of the present invention,and it should be understood that the technical scope of the presentinvention includes all modifications, equivalents, and replacements thatwill be obvious to those skilled in the art.

The terms used in the invention are used only for the purpose ofexplaining particular embodiments and are not intended to limit theinvention by any means. The expression of singularity also includes theexpression of plurality, unless clearly stated otherwise in the context.It should be understood that the terms “including”, “comprising” or“having” as used in the invention are only intended to indicate theexistence of the features, values, stages, actions, constituentelements, component parts, or combinations thereof described in thespecification, and they do not indicate the exclusion of any otherfeatures, values, stages, actions, constituent elements, componentparts, and combinations thereof.

The composition for etching according to an embodiment of the inventioncomprises a first additive represented by Chemical Formula 1 below, anda solvent.

In Chemical Formula 1, X maybe O or N; R1 to R6 each, independently, maybe selected from the group consisting of hydrogen, a C1-C20 alkyl group,a C1-C20 alkoxy group, a C2-C20 alkenyl group, a C3-C20 cycloalkylgroup, a C1-C20 aminoalkyl group, a C6-C20 aryl group, a C1-C20 alkylcarbonyl group, a C1-C20 alkyl carbonyloxy group, and a C1-C10 cyanoalkyl group; n11 may be 0 or 1; and at least two of R1 to R4 may beC1-C20 alkoxy groups when n11 is 0.

The additive of Chemical Formula 1 may be represented by ChemicalFormula 2 when n11 is 0, and by Chemical Formula 3 when n11 is 1.

In Chemical Formulas 2 and 3, X and R1 to R6 may be defined in the sameway as they are defined for Chemical Formula 1.

By having the above structure, the first additive represented byChemical Formula 1 can improve the etching speed and selectivity of thesilicon nitride film and silicon oxide film by controlling the directionof growth of the silicon ions generated during the high temperatureetching process, and through end capping of the silicon ions. Further,the number of silicon particles generated during the etching process canbe reduced by controlling the linear structure of the silicon iongrowth, and silicon wafer yield can be improved by preventingself-coupling and self-reaction of the silicon ions through end cappingof the ions.

The content of the first additive may be 0.01% to 15% by weight,preferably 0.1% to 15% by weight, more preferably 0.1% to 10% by weight,and even more preferably 0.1% to 5% by weight, with respect to the totalweight of the composition for etching. When the content of the firstadditive is less than 0.01% by weight, high etch selectivity withrespect to a nitride film cannot be obtained, and when the contentexceeds 15% by weight, it is difficult to expect a further improvementin the effects associated with an increase in the content, while thethermal decomposition of the additive may rather reduce the effects.

Meanwhile, in addition to the first additive, the composition foretching may further comprise a second additive such as that describedbelow.

The second additive may include a silane inorganic acid salt produced byreacting a second inorganic acid with a silane compound. The silaneinorganic acid salt may control the etch rate of an oxide film, therebyfacilitating control of the effective field oxide height (EFH).

According to an embodiment, the silane inorganic acid salt may beproduced by reacting the second inorganic acid with the silane compound.Since the silane inorganic acid salt is produced by reacting the secondinorganic acid with the silane compound, the silane inorganic acid saltmay not be a compound having a single chemical structure, but may be amixture of silane inorganic acid salts having various chemicalstructures. That is, the second additive may include a mixture of atleast two or more silane inorganic acid salts having different chemicalstructures. However, the present invention is not limited thereto, andthe second additive may also include only one kind of silane inorganicacid salt.

The second inorganic acid may be any one selected from the groupconsisting of sulfuric acid, fuming sulfuric acid, nitric acid,phosphoric acid, anhydrous phosphoric acid, pyrophosphoric acid,polyphosphoric acid, and mixtures thereof, and is preferably sulfuricacid, nitric acid, or phosphoric acid.

The silane compound may be any one selected from the group consisting ofa compound represented by Chemical Formula 10 below, a compoundrepresented by Chemical Formula 20 below, and a mixture thereof.

In Chemical Formula 10, R1 to R4 each, independently, may be any oneselected from the group consisting of a hydrogen atom, a halogen atom, aC1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 aryl group; andat least one of R1 to R4 is a halogen atom or a C1-C10 alkoxy group.

The halogen atom may be a fluoro group, a chloro group, a bromo group,or an iodo group, and preferably a fluoro group or a chloro group.

Specifically, the compound represented by Chemical Formula 10 may be ahalosilane or an alkoxysilane compound.

The halosilane compound may be any one selected from the groupconsisting of trimethylchlorosilane, triethylchlorosilane,tripropylchlorosilane, trimethylfluorosilane, triethylfluorosilane,tripropylfluorosilane, dimethyldichlorosilane, diethyldichlorosilane,dipropyldichlorosilane, dimethyldifluorosilane, diethyldifluorosilane,dipropyldifluorosilane, ethyltrichlorosilane, propyltrichlorosilane,methyltrifluorosilane, ethyltrifluorosilane, propyltrifluorosilane, andmixtures thereof.

The alkoxysilane compound may be any one selected from the groupconsisting of tetramethoxysilane (TMOS), tetrapropoxysilane,methyltrimethoxysilane (MTMOS), methyltriethoxysilane (MTEOS),methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,ethyltripropoxysilane, propyltrimethoxysilane (PrTMOS),propyltriethoxysilane (PrTEOS), propyltripropoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,dimethyldipropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane,diethyldipropoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane,dipropyldipropoxysilane, trimethylmethoxysilane, trimethylethoxysilane,trimethylpropoxysilane, triethylmethoxysilane, triethylethoxysilane,triethylpropoxysilane, tripropylmethoxysilane, tripropylethoxysilane,tripropylpropoxysilane, 3-chloropropyltrimethoxysilane,3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,[3-(2-aminoethyl)aminopropyl]trimethoxysilane,3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane,3-acryloxypropyltrimethoxysilane, and mixtures thereof.

In Chemical Formula 20, R5 to R10 each, independently, may be any oneselected from the group consisting of a hydrogen atom, a halogen atom, aC1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 aryl group; atleast one from among R5 to R10 is a halogen atom or a C1-C10 alkoxygroup; and n represents an integer from 1 to 10.

The halogen atom may be a fluoro group, a chloro group, a bromo group,or an iodo group, and the halogen atom is preferably a fluoro group or achloro group.

Specifically, examples of the compound represented by Chemical Formula20 include chlorodimethylsiloxy-chlorodimethylsilane,chlorodiethylsiloxy-chlorodimethylsilane,dichloromethylsiloxy-chlorodimethylsilane,dichloroethylsiloxy-chlorodimethylsilane,trichlorosiloxy-chlorodimethylsilane,fluorodimethylsiloxy-chlorodimethylsilane,difluoromethylsiloxy-chlorodimethylsilane,trifluorosiloxy-chlorodimethylsilane,methoxydimethylsiloxy-chlorodimethylsilane,dimethoxymethylsiloxy-chlorodimethylsilane,trimethoxysiloxy-chlorodimethylsilane,ethoxydimethylsiloxy-chlorodimethylsilane,diethoxymethylsiloxy-chlorodimethylsilane,triethoxysiloxy-chlorodimethylsilane,chlorodimethylsiloxy-dichloromethylsilane,trichlorosiloxy-dichloromethylsilane,chlorodimethylsiloxy-trichlorosilane,dichloromethylsiloxy-trichlorosilane, andtrichlorosiloxy-trichlorosilane.

The silane inorganic acid salt may be produced by adding the silanecompound to the second inorganic acid, and then reacting the mixture ata temperature of 20° C. to 300° C., and preferably 50° C. to 200° C. Atthis time, the reaction may be carried out while removing the air andmoisture. When the reaction temperature is below 20° C., the silanecompound may be crystallized, or the silane compound may evaporate dueto a low reaction rate. When the reaction temperature exceeds 300° C.,the second inorganic acid may be vaporized.

The second inorganic acid and the silane compound may be reacted at aproportion of the silane compound of 0.001 to 50 parts by weight, andpreferably 0.01 to 30 parts by weight, with respect to 100 parts byweight of the second inorganic acid. When the amount of the silanecompound reacted is less than 0.001 parts by weight, the realization ofselectivity may be difficult due to the small content ratio of thesilane compound, and when the amount exceeds 50 parts by weight, thesilane compound may be precipitated, or an amorphous structure may beproduced.

Volatile side products that are generated at the time of reaction may beremoved by distillation under reduced pressure. The product of theabove-described reaction may be purified to separate the silaneinorganic acid salt, which may then be added to the composition foretching. Alternatively, it is also possible to add the reaction productto the composition for etching without purification.

The reaction may be carried out in the presence or absence of an aproticsolvent, and in the case of using an aprotic solvent, a solvent orsolvent mixture having a boiling point or a boiling range up to 120° C.at 10,013 mbar may preferably be used. Examples of the solvent includedioxane; tetrahydrofuran; diethyl ether; diisopropyl ether; diethyleneglycol dimethyl ether; chlorinated hydrocarbons, for example,dichloromethane, trichloromethane, tetrachloromethane,1,2-dichloroethane, and trichloroethylene; hydrocarbons, for example,pentane, n-hexane, a mixture of hexane isomers, heptane, octane,benzine, petroleum ether, benzene, toluene, and xylene; ketones, forexample, acetone, methyl ethyl ketone, diisopropyl ketone, and methylisobutyl ketone (MIBK); esters, for example, ethyl acetate, butylacetate, propyl propionate, ethyl butyrate, ethyl isobutyrate, carbondisulfide, and nitrobenzene; and mixtures thereof.

As described above, since the silane inorganic acid salt is produced byreacting the second inorganic acid with the silane compound, the silaneinorganic acid salt may not be a compound having a single chemicalstructure, but may be a mixture of silane inorganic acid salts havingvarious chemical structures. That is, the silane inorganic acid saltsmay be a product resulting from alternate reactions between the secondinorganic acid and the silane compound, or may be a mixture of silaneinorganic acid salts having various chemical structures obtained as aresult of reacting into a linear form or a branched form, depending onthe number and positions of the halogen atoms in the silane compound.

Specific examples of the silane inorganic acid salts having variouschemical structures include the compounds of the chemical formulasbelow. However, the silane inorganic acid salt of the present inventionis not limited thereto.

In Chemical Formulas 51 to 57, 61 to 67, and 71 to 77, R1-1 to R1-8each, independently, may be any one selected from the group consistingof a hydrogen atom, a halogen atom, a C1-C10 alkyl group, a C1-C10alkoxy group, and a C6-C30 aryl group; and the halogen atom may be afluoro group, a chloro group, a bromo group, or an iodo group, while itis preferably a fluoro group or a chloro group.

The content of the silane inorganic acid salt may be 0.01% to 15% byweight, preferably 0.1% to 15% by weight, more preferably 0.1% to 10% byweight, and even more preferably 0.1% to 5% by weight, with respect tothe total weight of the composition for etching. When the content of thesilane inorganic acid salt is less than 0.01% by weight, a high etchselectivity for a nitride film cannot be obtained, and when the contentexceeds 15% by weight, it is difficult to expect a further increase inthe effects associated with an increase in the content, and there mayrather be problems such as particle generation.

According to another embodiment, the silane inorganic acid salt may beproduced by reacting polyphosphoric acid with the silane compoundrepresented by Chemical Formula 10. At this time, the silane inorganicacid salt may be represented by Chemical Formula 100 below.

In Chemical Formula 100, R1 may be any one selected from the groupconsisting of a hydrogen atom, a halogen atom, a C1-C10 alkyl group, aC1-C10 alkoxy group, and a C6-C30 aryl group; the halogen atom may be afluoro group, a chloro group, a bromo group, or an iodo group, but ispreferably a fluoro group or a chloro group; n₁ is an integer from 1 to4; m₁ is an integer from 1 to 10; and R2 to R4 each represent a hydrogenatom. However, optionally, any one hydrogen atom selected from among thegroup consisting of R2 to R4 may be substituted by a substituentrepresented by Chemical Formula 120 below.

In Chemical Formula 120, any one of the R5 groups is a linking grouplinked to a structure represented by Chemical Formula 100, and theothers each, independently, may be any one selected from the groupconsisting of a hydrogen atom, a halogen atom, a C1-C10 alkyl group, aC1-C10 alkoxy group, and a C6-C30 aryl group. That is, in the case inwhich there are four units of R5, one of them is a linking group linkedto the structure of Chemical Formula 100, and the remaining three may beeach, independently, any one selected from the group consisting of ahydrogen atom, a halogen atom, a C1-C10 alkyl group, a C1-C10 alkoxygroup, and a C6-C30 aryl group. Furthermore, in the case in which thereis only one unit of R5, this R5 represents a linking group linked to thestructure of Chemical Formula 100.

Here, n₂ represents an integer from 0 to 3, and m₂ represents an integerfrom 1 to 10.

In Chemical Formula 120, R2 to R4 may each, independently, be a hydrogenatom, or may be substituted by a second substituent represented byChemical Formula 120. That is, a second substituent represented byChemical Formula 120 may be substituted at any one of the R2 to R4positions, and a third substituent represented by Chemical Formula 120may further be substituted at any one of the R2 to R4 positions of thesecond substituent represented by Chemical Formula 120. This is becausethe silane inorganic acid salt is produced by reacting thepolyphopshoric acid with the silane compound. That is, the compoundrepresented by Chemical Formula 100 is produced as a result of thereaction between the polyphosphoric acid and the silane compound, and ahydroxyl group at any one of the R2 to R4 positions of a moiety derivedfrom the polyphosphoric acid may react again with the silane compound,which is a reaction starting material. Subsequently, the silane compoundthat has reacted with the compound represented by Chemical Formula 100may react again with the polyphosphoric acid, which is a reactionstarting material, and such a reaction may proceed continuously.

An example of the silane inorganic acid salt resulting from thecontinuous procession of the reaction is as follows.

As an example, in Chemical Formula 100, in the case in which n₁ is 1, m₁is 1, and R2 to R4 are all hydrogen atoms, the compound may beequivalent to Chemical Formula 101 below. Here, the definitions for R1-1to R1-3 are the same as the definition for R1.

A compound represented by Chemical Formula 102 below is the same as thecompound represented by Chemical Formula 101, except that m₁ is 2.

As another example, in Chemical Formula 100, in the case in which n₁ is2, m₁ is 1, and R2 to R4 all represent hydrogen atoms, the compound maybe equivalent to Chemical Formula 103 below. Here, the definitions forR1-1 and R1-2 are the same as the definition for R1.

In Chemical Formula 100, in an example of the case in which n₁ is 1, m₁is 1, R2 and R3 both represent a hydrogen atom, and R4 is substituted bya substituent represented by Chemical Formula 120, the compound may beequivalent to Chemical Formula 104 below. In Chemical Formula 120, n₂ is0, and any one of the R5 groups is a linking group linked to a structurerepresented by Chemical Formula 100. Here, the definitions for R1-1 toR1-6 are the same as the definition for R1. A compound represented byChemical Formula 104 below is a resultant product produced when a moietyderived from the polyphosphoric acid and having a substituentrepresented by R4 in the compound represented by Chemical Formula 100reacts again with the silane compound as a reaction starting substance.

In Chemical Formula 100, as an example of the case in which n₁ is 1, m₁is 1, R3 and R4 are each hydrogen atoms, and R2 is substituted with asubstituent represented by Chemical Formula 120, the compound may beequivalent to Chemical Formula 105 below. In Chemical Formula 120, n₂ is1, m₂ is 1, any one of the R5 groups represents a linking group linkedto a structure represented by Chemical Formula 100, and R2 to R4 allrepresent hydrogen atoms. Here, the definitions for R1-1 to R1-5 are thesame as the definition for R1 described above. A compound represented byChemical Formula 105 below is a resultant product produced when ahydroxyl group at any one of the R4 positions of a moiety derived fromthe polyphosphoric acid in the compound represented by Chemical Formula100 reacts again with the silane compound as a reaction startingsubstance, and subsequently the silane compound that has reacted withthe compound represented by Chemical Formula 100 reacts again with thepolyphosphoric acid as a reaction starting substance.

Compounds represented by Chemical Formulas 106 and 107 below are thesame as the compound represented by Chemical Formula 105, except thatthe position of the substituent represented by Chemical Formula 120 hasbeen changed from the R2-position of Chemical Formula 100 to the R3- andR4-position, respectively.

In Chemical Formula 100, in an example of the case in which n₁represents 1; m₁ represents 1; R2 and R3 each represent a hydrogen atom;R4 is substituted by a substituent represented by Chemical Formula 120;and a second substituent represented by Chemical Formula 120 issubstituted at the R4-position of the substituent represented byChemical Formula 120, the compound may be equivalent to Chemical Formula108 below. In Chemical Formula 120, n₂ represents 1; m₂ represents 1;any one of the R5's represents a linking group linked to a structurerepresented by Chemical Formula 100; and R2 and R3 are hydrogen atoms.At this time, the definitions for R1-1 to R1-7 are the same as thedefinition for R1 described above. A compound represented by ChemicalFormula 108 below is a resultant product produced when a hydroxyl groupof a moiety derived from the polyphosphoric acid on the right-hand sideterminal of the compound represented by Chemical Formula 107 reactsagain with the silane compound as a reaction starting substance, andsubsequently the silane compound that has reacted with the compoundrepresented by Chemical Formula 107 reacts again with the polyphosphoricacid as a reaction starting substance.

The present invention is not intended to be limited to the compoundsexemplified by Chemical Formulas 101 to 108, and various modificationscan be made based on the compounds described above as references.

Meanwhile, the silane compound that can react with the polyphosphoricacid and thereby produce the silane inorganic acid salt represented byChemical Formula 100 may be a compound represented by Chemical Formula10 described above. The details of the compound represented by ChemicalFormula 10 are as described above.

The polyphosphoric acid may be pyrophosphoric acid, containing twophosphorus atoms, or a polyphosphoric acid, containing three or morephosphorus atoms.

The method of manufacturing the silane inorganic acid salt by reactingthe polyphosphoric acid with the silane compound is the same as themethod of manufacturing the silane inorganic acid salt by reacting thesecond inorganic acid with the silane compound, except that thepolyphosphoric acid is used instead of the second inorganic acid.

According to an embodiment, the silane inorganic acid salt may be asiloxane inorganic acid salt produced by reacting any one of the secondinorganic acids selected from the group consisting of phosphoric acid,phosphoric acid anhydride, pyrophosphoric acid, polyphosphoric acid, andmixtures thereof, with a siloxane compound represented by ChemicalFormula 20.

Here, the siloxane inorganic acid salt may be represented by ChemicalFormula 200 below.

In Chemical Formula 200, R1 and R2 each, independently, represent anyone selected from the group consisting of a hydrogen atom, a halogenatom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 arylgroup, wherein the halogen atom may be a fluoro group, a chloro group, abromo group, or an iodo group, while the halogen atom is preferably afluoro group or a chloro group.

Here, n1 represents an integer from 0 to 3; n₂ represents an integerfrom 0 to 2; m₁ represents an integer of 0 or 1; and the relationn₁+n₂+m1≥1 is satisfied. That is, Chemical Formula 200 includes at leastone atomic group derived from the second inorganic acid, such asphosphoric acid.

l₁ represents an integer from 1 to 10; and o₁ to o₃ each, independently,represent an integer from 0 to 10.

Further, R3 to R11 each represent a hydrogen atom. However, any onehydrogen atom selected from the group consisting of R3 to R11 mayoptionally be substituted by a substituent represented by ChemicalFormula 220 below.

In Chemical Formula 220, any one of the R12's and R13's is a linkinggroup linked to a structure represented by Chemical Formula 200, and theothers each, independently, represent any one selected from the groupconsisting of a hydrogen atom, a halogen atom, a C1-C10 alkyl group, aC1-C10 alkoxy group, and a C6-C30 aryl group. That is, in a case inwhich there are two units of R12 and one unit of R13, one of them is alinking group linked to a structure represented by Chemical Formula 200,while the other two may each, independently, represent any one selectedfrom the group consisting of a hydrogen atom, a halogen atom, a C1-C10alkyl group, a C1-C10 alkoxy group, and a C6-C30 aryl group. Further, ina case in which there is one unit of R12 and zero units of R13, R12 is alinking group linked to a structure represented by Chemical Formula 200.

Here, n₃ represents an integer from 0 to 3; n₄ represents an integerfrom 0 to 2; and m₁ represents an integer of 0 or 1. l₁ represents aninteger from 1 to 10, and o₁ to o₃ each, independently, represent aninteger from 0 to 10.

Additionally, R3 to R11 may each, independently, represent a hydrogenatom, or they may each, independently, be substituted by a secondsubstituent represented by Chemical Formula 220. That is, a secondsubstituent represented by Chemical Formula 220 may be substituted atany one of the R3-to R11-positions, and a third substituent representedby Chemical Formula 220 may also be substituted at any one of the R3- toR11-positions of the second substituent represented by Chemical Formula220.

This is because the siloxane inorganic acid salt is a product producedby reacting the second inorganic acid with the siloxane compound. Thatis, the second inorganic acid reacts with the siloxane compound, and acompound represented by Chemical Formula 200 described above isproduced. A hydroxyl group at any one of the R3- to R11-positions of amoiety derived from the second inorganic acid in the compoundrepresented by Chemical Formula 200 can react again with the siloxanecompound as a reaction starting substance, and subsequently, thesiloxane compound that has reacted with the compound represented byChemical Formula 200 can react again with the second inorganic acid as areaction starting substance. Thus, these reactions can proceedcontinuously.

The resultant siloxane inorganic acid salts obtained by the successiveprogression of the reaction above are exemplified as follows.

In Chemical Formula 200, as an example of the case in which n₁represents 1; n₂ represents zero; m₁ represents zero; l₁ represents 1;o₁ to o₃ each represent zero; and R3 to R11 all represent a hydrogenatom, the compound may be equivalent to Chemical Formula 201 below.Here, the definitions for R1- and R1-2 are the same as the definitionfor R1 described above, and the definitions for R2-1 and R2-2 are thesame as the definition for R2 described above.

A compound represented by Chemical Formula 202 below may be the same asa compound represented by Chemical Formula 201, except that n₂ is 1.

A compound represented by Chemical Formula 203 below may be the same asa compound represented by Chemical Formula 201, except that o₂ and o₃are both 1.

A compound represented by Chemical Formula 204 below may be the same asa compound represented by Chemical Formula 202, except that l₁ is 2.

In Chemical Formula 200, in an example of the case in which n₁ and n₂each represent 2; m₁ represents zero; l₁ represents 1; o₁ to o₃ eachrepresent zero; and R3 to R11 all represent a hydrogen atom, thecompound may be equivalent to Chemical Formula 205 below.

In Chemical Formula 200, in an example of the case in which n₁represents 1; n₂ represents 1; m₁ represents zero; l₁ represents 1; o₁to o₃ each represent zero; R6, R9, and R11 each represent a hydrogenatom; and R8 is substituted by a substituent represented by ChemicalFormula 220, the compound may be equivalent to Chemical Formula 206below. In Chemical Formula 220, n₃ and n₄ each represent zero; m₁represents zero; l₁ represents 1; and any one of the R12's is a linkinggroup linked to a structure represented by Chemical Formula 200. Here,the definitions for R1-1 to R1-7 are the same as the definition for R1,and the definition for R2-1 is the same as the definition for R2. Acompound represented by Chemical Formula 206 below is a resultantproduct produced when a hydroxyl group at the R8-position of a moietyderived from the second inorganic acid in the compound represented byChemical Formula 200 reacts again with the siloxane compound as areaction starting substance.

In Chemical Formula 200, in an example of the case in which n₁represents 1; n₂ represents 1; m₁ represents zero; l₁ represents 1; o₁to o₃ each represent zero; R6, R9, and R11 each represent a hydrogenatom; and R8 is substituted by a substituent represented by ChemicalFormula 220, the compound may be equivalent to Chemical Formula 207below. In Chemical Formula 220, n₃ and n₄ each represent 1; m₁represents zero; o₂ and o₃ each represent zero; any one of the R12's isa linking group linked to a structure represented by Chemical Formula200; and R6, R8, R9, and R11 each represent a hydrogen atom. Here, thedefinitions for R1-1 to R1-3 are the same as the definition for R1; thedefinitions for R2-1 and R2-2 are the same as the definition for R2; andthe definitions for R3-1 and R3-2 are the same as the definition for R3.A compound represented by Chemical Formula 207 below is a resultantproduct produced when a hydroxyl group at the R8-position of a moietyderived from the second inorganic acid in the compound represented byChemical Formula 200 reacts again with the siloxane compound as areaction starting substance, and subsequently, the siloxane compoundthat has reacted with the compound represented by Chemical Formula 200reacts again with the second inorganic acid as a reaction startingsubstance.

A compound represented by Chemical Formula 208 below may be the same asa compound represented by Chemical Formula 207, except that thesubstituent represented by Chemical Formula 220 is linked to ChemicalFormula 200 at the R1-3-position of Chemical Formula 207.

In Chemical Formula 200, in an example of the case in which n₁represents 1; n₂ represents 1; m₁ represents 0; l₁ represents 1; o₁ too₃ each represent zero; R3, R6, R9, and R11 each represent a hydrogenatom; R8 is substituted by a first substituent represented by ChemicalFormula 220; and R8 of the first substituent represented by ChemicalFormula 220 is substituted by a second substituent represented byChemical Formula 220, the compound may be equivalent to Chemical Formula209 below. In the first substituent represented by Chemical Formula 220,n₃ and n₄ each represent 1; m₁ represents zero; l₁ represents 1; o₂ ando₃ each represent zero; any one of the R12's is a linking group linkedto a structure represented by Chemical Formula 200; R6, R9, and R11 eachrepresent a hydrogen atom; and R8 represents a second substituentrepresented by Chemical Formula 220. In the second substituentrepresented by Chemical Formula 220, n₃ and n₄ each represent 1; m₁represents 0; l₁ represents 1; o₂ and o₃ each represent zero; any one ofthe R12's represents a linking group linked to the first substituentrepresented by Chemical Formula 220; and R6, R8, R9, and R11 eachrepresent a hydrogen atom. Here, the definitions for R1-1 to R1-4 arethe same as the definition for R1; the definitions for R2-1 to R2-3 arethe same as the definition for R2; and the definitions for R3-1 to R3-3are the same as the definition for R3.

A compound represented by Chemical Formula 209 below is a resultantproduct produced when a moiety derived from the second inorganic acid atthe right-hand end of the compound represented by Chemical Formula 207is reacted again with the siloxane compound as a reaction startingsubstance, and subsequently, the siloxane compound that has reacted withthe compound represented by Chemical Formula 207 reacts again with thesecond inorganic acid as a reaction starting substance.

A compound represented by Chemical Formula 210 below may be the same asa compound represented by Chemical Formula 209, except that the secondsubstituent represented by Chemical Formula 220 is linked to a structurerepresented by Chemical Formula 200 at the R1-4-position of ChemicalFormula 209.

The present invention is not intended to be limited to the compoundsrepresented by Chemical Formulas 201 to 210, and various modificationscan be made based on the compounds described above.

According to an embodiment, the silane inorganic acid salt may be asiloxane inorganic acid salt produced by reacting any one of the secondinorganic acids selected from the group consisting of sulfuric acid,fuming sulfuric acid, and a mixture thereof, with the siloxane compoundrepresented by Chemical Formula 20.

Here, the siloxane inorganic acid salt may be represented by ChemicalFormula 230 below.

In Chemical Formula 230, R21 and R22 each, independently, represent anyone selected from the group consisting of a hydrogen atom, a halogenatom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 arylgroup, wherein the halogen atom may be a fluoro group, a chloro group, abromo group, or an iodo group, while the halogen atom is preferably afluoro group or a chloro group.

Further, n₁ represents an integer from 0 to 3; n₂ represents an integerfrom 0 to 2; m₁ represents an integer of 0 or 1; and the relationn₁+n₂+m₁≥1 is satisfied. That is, Chemical Formula 230 contains at leastone atomic group derived from the second inorganic acid, such assulfuric acid.

l₁ represents an integer from 1 to 10.

R23 to R25 each represent a hydrogen atom. However, any one hydrogenselected from the group consisting of R23 to R25 may optionally besubstituted by a substituent represented by Chemical Formula 250 below.

In Chemical Formula 250, any one of the R26's and R27's is a linkinggroup linked to a structure represented by Chemical Formula 230, whilethe others each, independently, represent any one selected from thegroup consisting of a hydrogen atom, a halogen atom, a C1-C10 alkylgroup, a C1-C10 alkoxy group, and a C6-C30 aryl group. That is, in acase in which there are two units of R26 and one unit of R27, one ofthem is a linking group linked to a structure represented by ChemicalFormula 230, while the other two may each, independently, represent anyone selected from the group consisting of a hydrogen atom, a halogenatom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 arylgroup. Furthermore, in a case in which there is only one unit of R26 andzero units of R27, R26 is a linking group linked to a structurerepresented by Chemical Formula 230.

Further, n₃ represents an integer from 0 to 3; n₄ represents an integerfrom 0 to 2; m₁ represents an integer of 0 or 1; and l₁ represents aninteger from 1 to 10.

R23 to R25 may each, independently, represent a hydrogen atom, or may besubstituted by a second substituent represented by Chemical Formula 250.That is, a second substituent represented by Chemical Formula 250 may besubstituted at any one of the R23- to R25-positions, and a thirdsubstituent represented by Chemical Formula 250 may be substituted againat any one of the R23- to R25-positions.

When the resultant siloxane inorganic acid salt obtained by thesuccessive progression of the reactions as described above areexemplified similarly to the cases of Chemical Formulas 201 to 210, theexamples include compounds represented by Chemical Formulas 231 to 239below. Here, in the following Chemical Formulas 231 to 239, thedefinitions for R11-1 to R11-7 are the same as the definition for R11;the definitions for R12-1 to R12-3 are the same as the definition forR12; and the definitions for R13-1 to R13-3 are the same as thedefinition for R13.

The present invention is not limited to the compounds exemplified aboveby Chemical Formulas 231 to 239, and various modifications can be madebased on the above-described compounds as references.

According to another embodiment, the silane inorganic acid salt may be asiloxane inorganic acid salt produced by reacting a second inorganicacid comprising nitric acid with the siloxane compound represented byChemical Formula 20.

At this time, the siloxane inorganic acid salt may be represented byChemical Formula 260 below.

In Chemical Formula 260, R31 and R32 each, independently, represent anyone selected from the group consisting of a hydrogen atom, a halogenatom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 arylgroup, wherein the halogen atom may be a fluoro group, a chloro group, abromo group, or an iodo group, while the halogen atom is preferably afluoro group or a chloro group.

Further, n₁ represents an integer from 0 to 3; n₂ represents an integerfrom 0 to 2; m₁ represents an integer of 0 or 1; and the relationn₁+n₂+m₁≥1 is satisfied. That is, Chemical Formula 260 contains at leastone atomic group derived from the second inorganic acid comprisingnitric acid.

Additionally, l₁ represents an integer from 1 to 10.

R33 to R35 each, independently, represent a hydrogen atom. However, anyone hydrogen selected from the group consisting of R33 to R35 mayoptionally be substituted by a substituent represented by ChemicalFormula 280 below.

In Chemical Formula 280, any one of the R36's and R37's is a linkinggroup linked to a structure represented by Chemical Formula 260, whilethe others each, independently, represent any one selected from thegroup consisting of a hydrogen atom, a halogen atom, a C1-C10 alkylgroup, a C1-C10 alkoxy group, and a C6-C30 aryl group. That is, in acase in which there are two units of R36 and one unit of R37, one ofthem is a linking group linked to a structure represented by ChemicalFormula 260, while the other two may each, independently, represent anyone selected from the group consisting of a hydrogen atom, a halogenatom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C6-C30 arylgroup. Furthermore, in a case in which there is only one unit of R36 andzero units of R37, R36 is a linking group linked to a structurerepresented by Chemical Formula 260.

Further, n₃ represents an integer from 0 to 3; n₄ represents an integerfrom 0 to 2; m₁ represents an integer of 0 or 1; and l₁ represents aninteger from 1 to 10.

R33 to R35 may each, independently, represent a hydrogen atom, or theymay be each substituted by a second substituent represented by ChemicalFormula 280. That is, the second substituent represented by ChemicalFormula 280 may be substituted at any one of the R33- to R35-positions,and a third substituent represented by Chemical Formula 280 may besubstituted again at any one of the R33- to R35-positions of the secondsubstituent represented by Chemical Formula 280.

When the resultant siloxane inorganic acid salt obtained by thesuccessive progression of the reactions as described above areexemplified similarly to the cases of Chemical Formulas 201 to 210, theexamples include compounds represented by Chemical Formulas 261 to 269below. Here, in Chemical Formulas 261 to 269 below, the definitions forR21-1 to R21-7 are the same as the definition for R21; the definitionsfor R22-1 to R22-3 are the same as the definition for R22; and thedefinitions for R23-1 to R23-3 are the same as the definition for R23.

The present invention is not intended to be limited to the compoundsexemplified by Chemical Formulas 261 to 269, and various modificationscan be made based on the above-described compounds as references.

Meanwhile, the siloxane compound that can react with the secondinorganic acid to produce the siloxane inorganic acid salt representedby Chemical Formula 200 may be a compound represented by ChemicalFormula 20. The details of the compound represented by Chemical Formula20 are as described above.

The method of manufacturing the siloxane inorganic acid salt by reactingthe second inorganic acid with a siloxane compound is the same as themethod of manufacturing the silane inorganic acid salt by reacting thesecond inorganic acid with a silane compound, except that a siloxanecompound is used instead of a silane compound.

Furthermore, the second additive may include an alkoxysilane compoundrepresented by Chemical Formula 300 below.

In Chemical Formula 300, R1 to R4 each, independently, represent any oneselected from the group consisting of a hydrogen atom, a halogen atom, ahydroxyl group, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C1-C10aminoalkyl group, a C1-C10 aminoalkoxy group, and a C6-C30 aryl group;and at least one of R1 to R4 represents a C1-C10 alkoxy group, a C1-C10aminoalkyl group, or a C1-C10 aminoalkoxy group.

Specifically, the alkoxysilane compound represented by Chemical Formula300 may be any one selected from the group consisting oftetramethoxysilane (TMOS), tetrapropoxysilane, methyltrimethoxysilane(MTMOS), methyltriethoxysilane (MTEOS), methyltripropoxysilane,ethyltrimethoxysilane, ethyltriethoxysilane, ethylthripropoxysilane,propyltrimethoxysilane (PrTMOS), propyltriethoxysilane (PrTEOS),propyltripropoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane,dimethyldipropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane,diethyldipropoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane,dipropyldipropoxysilane, trimethylmethoxysilane, trimethylethoxysilane,trimethylpropoxysilane, triethylmethoxysilane, triethylethoxysilane,triethylpropoxysilane, tripropylmethoxysilane, tripropylethoxysilane,tripropylpropoxysilane, 3-chloropropyltrimethoxysilane,3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,[3-(2-aminoethyl)aminopropyl]trimethoxysilane,3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane,3-acryloxypropyltrimethoxysilane, and mixtures thereof. Furthermore, thealkoxysilane compound represented by Chemical Formula 300 may be any oneselected from the group consisting of butyl(methoxy)dimethylsilane,3-cyanopropyldimethylmethoxysilane, trimethylethoxysilane,trimethylmethoxysilane, hexyldimethoxysilane, methyldiethoxysilane,4-aminobutyldimethylmethoxysilane, 3-aminopropyldimethylethoxysilane,butyltrimethoxysilane, ethyltriethoxysilane, isobutyltriethoxysilane,methyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane,triethoxysilane, butyltriethoxysilane, trimethylpentylsilane,3-(2-aminoethyl)aminopropyltrimethoxysilane,3-aminopropyltriethoxysilane, tris(dimethylamino)silane, and mixturesthereof.

Additionally, the second additive may include a siloxane compoundrepresented by Chemical Formula 350 below.

In Chemical Formula 350, R2 to R5 each, independently, represent any oneselected from the group consisting of a hydrogen atom, a halogen atom, ahydroxyl group, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C1-C10aminoalkyl group, a C1-C10 aminoalkoxy group, and a C6-C30 aryl group;at least one of R2 to R5 represents a C1-C10 alkoxy group, a C1-C10aminoalkyl group, or a C1-C10 aminoalkoxy group; and n represents aninteger from 1 to 4.

Specifically, the siloxane compound represented by Chemical Formula 350may be any one selected from the group consisting oftris(trimethylsiloxy)silane, tetrakis(trimethylsiloxy)silane,(aminopropyl)tris(trimethylsiloxy)silane,(aminopropyl)tris(diethylaminosiloxy)silane,(aminopropyl)tris(methylethylaminosiloxy)silane,tris(trimethylsiloxy)methylsilane, tris(diethylaminosiloxy)methylsilane,tris(methylethylaminosiloxy)methylsilane, and mixtures thereof.

In the alkoxysilane compound represented by Chemical Formula 300 or thesiloxane compound represented by Chemical Formula 350, the bond betweena silicon atom and an oxygen atom is unstable, and is likely to beeasily broken. However, in a case in which the alkoxysilane compoundrepresented by Chemical Formula 300 or the siloxane compound representedby Chemical Formula 350 contains an amino group, the atomic groupcontaining an amino group can stabilize the bond between a silicon atomand an oxygen atom. That is, the production of reaction side productsthat may be generated as a result of breakage of the unstable bondbetween a silicon and oxygen atom can be minimized. Therefore, theamount of particles produced during the etching process can beminimized, thereby facilitating the minimization of defects that mayoccur in the subsequent processes due to particles.

Further, the oxygen atoms included in the alkoxysilane compoundrepresented by Chemical Formula 300 or the siloxane compound representedby Chemical Formula 350 can be bonded to the surface of an oxide film toprotect the oxide film. For instance, the oxygen atoms included in thealkoxysilane compound represented by Chemical Formula 300 or thesiloxane compound represented by Chemical Formula 350 may form hydrogenbonds with the surface of an oxide film, and thus, etching of an oxidefilm which occurs during the etching of a nitride can be minimized.Therefore, the etch selectivity for a nitride film with respect to anoxide film can be increased.

Additionally, the second additive may include an oxime compoundrepresented by Chemical Formula 400 below. When the composition foretching includes the oxime compound represented by Chemical Formula 400,the etch rate for a silicon oxide film can be minimized, while asatisfactory etch rate and etch speed for a silicon nitride film can besecured. That is, when a silicon nitride film and a silicon oxide filmlayer exist together, it is possible to obtain an effect of etching onlythe silicon nitride film with almost no etching influence on the siliconoxide film. Furthermore, in the case of using the oxime compoundrepresented by the Chemical Formula 400 together with the alkoxysilanecompound represented by Chemical Formula 300 or the siloxane compoundrepresented by Chemical Formula 350, the solubility of these compoundscan be increased.

In Chemical Formula 400, R1 and R2 each, independently, represent anyone selected from the group consisting of a hydrogen atom, a halogenatom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C2-C20 alkenylgroup, a C3-C20 cycloalkyl group, a C1-C20 aminoalkyl group, a C6-C20aryl group, a C1-C20 alkylcarbonyl group, a C1-C20 alkylcarbonyloxygroup, and a C1-C10 cyanoalkyl group.

Specifically, the oxime compound may be any one selected from the groupconsisting of acetone oxime, 2-butanone oxime, acetaladehyde oxime,cyclohexanone oxime, acetophenone oxime, cyclodecanone oxime, andmixtures thereof.

The second additive may also include an oxime silane compoundrepresented by Chemical Formula 500 below. In a case in which thecomposition for etching includes the oxime silane compound representedby Chemical Formula 500, the etch rate for a silicon oxide film can beminimized, while a satisfactory etch rate and etch speed for a siliconnitride film can be secured. That is, when a silicon nitride film and asilicon oxide film layer exist together, it is possible to obtain aneffect of etching only the silicon nitride film with almost no etchinginfluence on the silicon oxide film. Furthermore, a high etch rate andetch selectivity can be obtained compared to conventional compositionsfor etching, and even in the case of being used for a long time period,there is no problem with a decrease in the etch rate for a siliconnitride film. Thus, the composition for etching can effectively beapplied during the production of semiconductor devices for which theselective etching of silicon nitride films is needed.

In Chemical Formula 500, R1 to R3 each, independently, represent any oneselected from the group consisting of a hydrogen atom, a halogen atom, aC1-C20 alkyl group, a C2-C20 alkenyl group, a C3-C20 cycloalkyl group, aC6-C20 aryl group, a C7-C20 arylalkyl group, and a C1-C20 alkylcarbonylgroup.

More specifically, R1 to R3 may each, independently, represent ahydrogen atom, a methyl group, an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, ahexyl group, a vinyl group, an acetyl group, a benzyl group, or a phenylgroup.

In Chemical Formula 500, R4 and R5 may each, independently, representany one selected from the group consisting of a C1-C20 alkyl group, aC3-C20 cycloalkyl group, a C6-C20 aryl group, a C7-C20 arylalkyl group,and a C1-C20 alkylcarbonyl group, or R4 and R5 may be linked to eachother as a C3-C12 alkylene group to form an alicyclic ring.

More specifically, R4 and R5 may each, independently, represent a methylgroup, an ethyl group, an n-propyl group, an isopropyl group, an n-butylgroup, a tert-butyl group, a pentyl group, a hexyl group, a benzylgroup, or a phenyl group, or R4 and R5 may be fused together to form acyclohexyl group.

In Chemical Formula 500, x, y, and z each, independently, represent aninteger from 0 to 3, and x+y+z represents an integer from 0 to 3.

Specifically, the oxime silane compound may be any one selected from thegroup consisting of di(ethyl ketoxime)silane, mono(ethy ketoxime)silane,tris(ethyl ketoxime)silane, tetra(ethyl ketoxime)silane, methyltris(methyl ethyl ketoxime)silane, methyl tris(acetoxime)silane, methyltris(methyl isobutyl ketoxime)silane, dimethyl di(methyl ethylketoxime)silane, trimethyl (methyl ethyl ketoxime)silane, tetra(methylethyl ketoxime)silane, tetra(methyl isobutyl ketoxime)silane, vinyltris(methyl ethyl ketoxime)silane, methyl vinyl di(methyl ethylketoxime)silane, vinyl tris(methyl isobutyl ketoxime)silane, and phenyltris(methyl ethyl ketoxime)silane.

Meanwhile, the first inorganic acid is added as an etching agent foretching a nitride film, and any inorganic acid capable of etching anitride film may be used. For example, any one selected from the groupconsisting of sulfuric acid, nitric acid, phosphoric acid, silicic acid,hydrofluoric acid, boric acid, hydrochloric acid, perchloric acid, andmixtures thereof may be used. The first inorganic acid, mixed with thesolvent in advance to form an aqueous solution, can be mixed with thefirst additive.

Phosphoric acid may preferably be used as the first inorganic acid inorder to achieve etch selectivity for a nitride film with respect to anoxide film. The phosphoric acid can play the role of supplying hydrogenions into the composition for etching, thereby accelerating the etchingprocess. In the case of using phosphoric acid as the first inorganicacid, the composition for etching may further include sulfuric acid asan additive. The sulfuric acid may be helpful in the etching of anitride film by elevating the boiling point of the composition foretching comprising phosphoric acid as the first inorganic acid.

The content of the first inorganic acid may be 70% to 99% by weight,preferably 70% to 90% by weight, and more preferably 75% to 85% byweight, with respect to the total weight of the composition for etching.When the first inorganic acid is included at a proportion of less than70% by weight, a nitride film may not be easily removed, and there is arisk that particle generation may occur. When the first inorganic acidis included at a proportion exceeding 99% by weight, high selectivityfor a nitride film cannot be obtained.

The composition for etching may include a solvent as the balance of theabove-mentioned components. Specifically, the solvent may be water,deionized water, or the like.

The composition for etching may further include an ammonium-basedcompound at a proportion of 0.01% to 20% by weight with respect to thetotal amount of the composition for etching. In a case in which thecomposition for etching further includes the ammonium-based compound,even if the composition for etching is used for a long time period, nochanges in the etching rate and etch selectivity occur, and there is aneffect of maintaining a constant etch rate.

When the ammonium-based compound is added in an amount of less than0.01% by weight, the effect of maintaining the etch selectivity when thecomposition for etching is employed over a long time period is reduced.When the ammonium-based compound is added in an amount in excess of 20%by weight, the etch rates for nitride films and silicon oxide films arechanged, and the etch selectivity may also be changed.

Regarding the ammonium-based compound, any one selected from an aqueousammonia solution, ammonium chloride, ammonium acetate, ammoniumphosphate, ammonium peroxydisulfate, ammonium sulfate, and ammoniumhydrofluoride, or a mixture of two or more kinds thereof may be used.Furthermore, the ammonium-based compound is not limited to theabove-described compounds, and any compound containing ammonium ions maybe used. For example, as the ammonium-based compound, NH₃ and HCl may beused together.

The composition for etching may further include a fluorine-basedcompound at a proportion of 0.01% to 1% by weight with respect to thetotal amount of the composition for etching. When the fluorine-basedcompound is added in an amount of less than 0.01% by weight, the etchrate for a nitride film is reduced, and the removal of a nitride filmmay become difficult. When the fluorine-based compound is added in anamount in excess of 1% by weight, the etch rate for a nitride film issignificantly increased; however, there is a disadvantage that an oxidefilm is also etched.

Regarding the fluorine-based compound, any one selected from hydrogenfluoride, ammonium fluoride, and ammonium hydrogen fluoride, or amixture of two or more kinds thereof may be used. More preferably, it isdesirable to use ammonium hydrogen fluoride because the etch selectivityis maintained upon long-term use.

Meanwhile, the composition for etching may further include any optionaladditives that are conventionally used in the related art in order toenhance the etching performance. Examples of the additives that may beused include a surfactant, a chelating agent, and a corrosion inhibitor.

Since the composition for etching includes the silane inorganic acidsalt described above, it can display markedly high etch selectivity fora nitride film with respect to an oxide film, and therefore, it may beused for a nitride film etching process.

Accordingly, the etching of an oxide film during an etching process canbe minimized, and thus the EFH can easily be regulated. Furthermore,upon the selective removal of a nitride film through etching,deterioration of the electrical characteristics caused by damage to thefilm quality of an oxide film as well as etching of an oxide film can beprevented, while also preventing particle generation, therebyfacilitating the enhancement of device characteristics.

A method of manufacturing a semiconductor device according to anotheraspect of the present invention includes an etching process employingthe composition for etching described above.

According to an embodiment, such an etching process involves etching ofa nitride film, and more particularly, selective etching of a nitridefilm with respect to an oxide film.

The nitride film may include silicon nitride films, for example, a SiNfilm and a SiON film.

Furthermore, the oxide film may be a silicon oxide film, for example, atleast one or more films selected from the group consisting of aspin-on-dielectric (SOD) film, a high-density plasma (HDP) film, athermal oxide film, a borophosphate silicate glass (BPSG) film, aphosphosilicate glass (PSG) film, a borosilicate glass (BSG) film, apolysilazane (PSZ) film, a fluorinated silicate glass (FSG) film, alow-pressure tetraethyl orthosilicate (LP-TEOS) film, a plasma-enhancedtetraethyl orthosilicate (PETEOS) film, a high temperature oxide (HTO)film, a medium temperature oxide (MTO) film, an undoped silicate glass(USG) film, a spin-on-glass (SOG) film, an advanced planarization layer(APL) film, an atomic layer deposition (ALD) film, a plasma-enhancedoxide (PE-oxide) film, an O3-tetraethyl orthosilicate (O3-TEOS) film,and combinations thereof.

An etching process employing the above-described composition for etchingmay be executed using any well-known wet etching method, for example, animmersion method or a spraying method.

During the etching process, the process temperature may be adjusted tothe range of 50° C. to 300° C., and preferably 100° C. to 200° C., andthe optimum temperature may be adjusted as necessary, in considerationof other processes and other factors.

According to a method of manufacturing a semiconductor device, whichincludes an etching process executed using the composition for etchingdescribed above, in a case in which nitride films and oxide films arealternately stacked or exist as a mixture, selective etching for nitridefilms is enabled. Furthermore, particle generation, which has been aproblem in conventional etching processes, can be prevented, and thusprocess stability and reliability can be secured.

Therefore, such a method can be efficiently applied to variousoperations where selective etching for a nitride film with respect to anoxide film is needed, in a semiconductor device production process.

FIG. 3, FIG. 4, and FIG. 5 are process cross-sectional views forexplaining a device separation process for a flash memory device,including an etching process employing the composition for etchingaccording to an embodiment of the present invention.

As shown in FIG. 3, a tunnel oxide film 21, polysilicon film 22, bufferoxide film 23, and pad nitride film 24 are sequentially formed on thesubstrate 20.

Subsequently, the pad nitride film 24, buffer oxide film 23, polysiliconfilm 22, and tunnel oxide film 21 are selectively etched throughphotolithography and etching processes, and thus, device separationregions of the substrate 20 are exposed.

Next, the exposed areas of the substrate 20 are selectively etched usingthe pad nitride film 24 as a mask, and trenches 25 having apredetermined depth from the surface are formed.

As depicted in FIG. 4, an oxide film 26 is formed over the entiresurface of a substrate 20 through a chemical vapor deposition (CVD)method or the like, until the trenches 25 are gap-filled.

Subsequently, a chemical mechanical polishing (CMP) process is performedfor oxide film 26 using the pad nitride film 24 as a polishing stopfilm.

Next, a washing process is performed using dry etching.

According to FIG. 5, the pad nitride film 24 is selectively removed by awet etching process employing the composition for etching according tothe present invention, and then the buffer oxide film 23 is removed by awashing process. Thereby, a device separation film 26A is formed in thefield region.

As illustrated in FIG. 5, according to the present invention, throughemployment of a high-selectivity composition for etching having a highselectivity for a nitride film with respect to an oxide film, nitridefilms can be completely and selectively removed during a sufficient timewhile the etching of oxide films gap-filled in an STI pattern isminimized. Accordingly, the effective oxide film height (EFH) can easilybe controlled, while deterioration of the electrical characteristicscaused by oxide film damage or etching, as well as particle generation,can be prevented, and thus the device characteristics can be enhanced.

The embodiments described above have been described with regard to flashmemory devices; however, the high-selectivity composition for etchingaccording to the present invention is also applicable to deviceseparation processes for DRAM devices.

FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. 10, and FIG. 11 are processcross-sectional views for explaining a process for forming channels in aflash memory device, including an etching process employing thecomposition for etching according to another embodiment of the presentinvention.

According to FIG. 6, a pipe gate electrode film 31 having a nitride film32 embedded therein, which is intended for forming pipe channelstherein, is formed on a substrate 30. A first conductive film 31A and asecond conducive film 31B that constitute the pipe gate electrode film31 may contain, for example, polysilicon doped with impurities.

More specifically, the first conductive film 31A is formed on thesubstrate 30, a nitride film is deposited on the first conductive film31A, and this nitride film is patterned to form a nitride film 32 forforming pipe channels. Subsequently, the second conductive film 31 b isformed on the first conductive film 31A that is exposed by the nitridefilm 32. The first conductive film 31A and second conductive film 31Bconstitute the pipe gate electrode film 31.

Next, in order to form a plurality of memory cells that are stacked onthe results of the process in a perpendicular direction, a firstinterlayer insulating film 33 and first gate electrode film 34 arealternately stacked. Hereinafter, for the convenience of description,the structure obtained by alternate stacking of the first interlayerinsulating films 33 and first gate electrode films 34 will be referredto as a cell gate structure (CGS).

Here, the first interlayer insulating films 33 are intended forproviding separation between a plurality of layers of memory cells, andmay comprise, for example, an oxide film. The first gate electrode film34 may comprise, for example, polysilicon doped with impurities. In thepresent embodiment, six layers of first gate electrode film 34 are shownin the diagram; however, the invention is not intended to be limitedthereto.

Subsequently, the cell gate structure (CGS) is selectively etched, andthereby a pair of first and second holes H1 and H2 that expose thenitride film 32 are formed. The first and second holes H1 and H2 arespaces for channel formation in memory cells.

As depicted in FIG. 7, a nitride film 35 that is embedded in the firstand second holes H1 and H2 is formed. This nitride film 35 is intendedfor preventing any damage that may occur when the first gate electrodefilm 34 is exposed by the first and second holes H1 and H2 in the trenchforming process that will be described below (see FIG. 8).

According to FIG. 8, the cell gate structure (CGS) existing between apair of first and second holes H1 and H2 is selectively etched, andthereby a trench S is formed, so that a plurality of layers of firstgate electrode film 34 are separated into portions corresponding to eachof the first hole and second hole H1 and H2.

According to FIG. 9, a sacrificial film 36 that is embedded in thetrench S is formed.

As shown in FIG. 10, a second interlayer insulating film 37, second gateelectrode film 38, and second interlayer insulating film 37 aresequentially formed on the process result, for the formation of aselection transistor. In the following description, for the convenienceof explanation, a layered structure comprising a second interlayerinsulating film 37, second gate electrode film 38, and second interlayerinsulating film 37 will be referred to as a selective gate structure(SGS).

The second interlayer insulating film 37 may comprise, for example, anoxide film, and the second gate electrode film 38 may comprise, forexample, polysilicon doped with impurities.

Subsequently, the selective gate structure (SGS) is selectively etched,and thereby, third and fourth holes H3 and H4 that expose the nitridefilm 35 embedded in the pair of first and second holes H1 and H2 areformed. The third and fourth holes H3 and H4 are regions in which thechannels of a selection transistor will be formed.

According to FIG. 11, the nitride film 35 that is exposed by the thirdand fourth holes H3 and H4, and the nitride film 32 disposed therebeloware selectively removed by a wet etching process employing thecomposition for etching according to the present invention.

As a result of the present process, a pair of cell channel holes H5 andH6 in which the channel films of the memory cell will be formed, and apipe channel hole H7 that is disposed below the cell channel holes H5and H6 and which connects these holes with each other, are formed. Here,by using the high-selectivity composition for etching according to thepresent invention, the nitride films are completely and selectivelyremoved during a sufficient time without loss of the oxide films, andthe pipe channels can therefore accurately be formed without loss of theprofile. Furthermore, particle generation, which has conventionallyposed a problem, can be prevented, and the safety and reliability of theprocesses can be secured.

Thereafter, subsequent process, for example, a floating gate formingprocess and a control gate forming process, are executed, and thus aflash memory device is formed.

FIG. 12 and FIG. 13 are process cross-sectional views explaining aprocess for forming a diode in a phase change memory device, includingan etching process employing the composition for etching according toanother embodiment of the present invention.

According to FIG. 12, an insulating structure having openings throughwhich a conductive region 41 is exposed is provided on a substrate 40.The conductive region 41 may be, for example, an n⁺ impurity region.

Subsequently, a polysilicon film 42 is formed so as to embed portions ofthe openings, and then ion implantation of impurities is carried out soas to form a diode.

Next, a titanium silicide film 43 is formed on top of the polysiliconfilm 42. The titanium silicide film 43 can be formed by forming atitanium film and then heat-treating the titanium film so as to reactwith the polysilicon film 42.

Subsequently, a titanium nitride film 44 and a nitride film 45 aresequentially formed on top of the titanium silicide film 43.

Next, a dry etching process is executed using a hard mask, and therebyan oxide film 46 is formed in an isolated space between the diodes thusformed. Subsequently, a CMP process is performed, and a primarystructure of lower electrodes that are separated from each other isformed.

As illustrated in FIG. 13, the process result is subjected to a wetetching process employing the composition for etching according to thepresent invention, and thus the nitride film 45 at the top isselectively removed. As such, through employment of the high-selectivitycomposition for etching according to the present invention, the nitridefilm can be completely and selectively removed during a sufficient timewithout loss of the oxide film. Furthermore, the deterioration ofelectrical characteristics caused by damage to the film quality of theoxide film and etching of the oxide film, as well as particlegeneration, can be prevented, and thus the device characteristics can beenhanced.

Titanium is subsequently deposited in the spaces where the nitride film45 has been removed, and thus lower electrodes are formed.

In addition to the processes described above, a method of manufacturinga semiconductor device which includes an etching process carried outusing the composition for etching of the present invention can beefficiently applied particularly to processes where the selectiveremoval of a nitride film is required, for example, to a process whereselective etching of a nitride film is required in a case in whichnitride films and oxide films are alternately stacked, or in which theyexist as a mixture.

Hereinafter, Examples of the present invention will be described indetail so that those having ordinary skill in the art to which thepresent invention pertains can easily execute the invention. However,the present invention can be realized in various different forms and isnot intended to be limited to the Examples described herein.

[Production Examples: Production of Compositions for Etching]

Example 1

A composition for etching was produced by mixing 99 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid and 1 wt % ofdimethyldimethoxysilane as a first additive.

Example 2

A composition for etching was produced by mixing 98 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid and 2 wt % ofdiethyldimethoxysilane as a first additive.

Example 3

A composition for etching was produced by mixing 99.5 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid and 0.5 wt % ofhexamethyldisiloxane as a first additive.

Example 4

A composition for etching was produced by mixing 99 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid and 1 wt % ofhexamethyldisilazane as a first additive.

Example 5

A composition for etching was produced by mixing 98.5 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid, 1 wt % ofdiethyldiethoxysilane as a first additive, and 0.5 wt % of a secondadditive represented by Chemical Formula 53-1, which is an additive inwhich the R1-1 group in Chemical Formula 53 is a methyl group.

Example 6

A composition for etching was produced by mixing 98.8 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid, 1 wt % ofdimethyldimethoxysilane as a first additive, and 0.2 wt % of an additiverepresented by Chemical Formula 53-1 as a second additive.

Example 7

A composition for etching was produced by mixing 99 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid, 0.5 wt % ofhexamethyldisiloxane as a first additive, and 0.5 wt % of an additiverepresented by Chemical Formula 53-1 as a second additive.

Example 8

A composition for etching was produced by mixing 98.8 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid, 1 wt % ofhexamethyldisilazane as a first additive, and 0.2 wt % of an additiverepresented by Chemical Formula 53-1 as a second additive.

Comparative Example 1

A composition for etching was produced by using 100 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid without a firstadditive and a second additive.

Comparative Example 2

A composition for etching was produced by using 99.5 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid and 0.5 wt % of anadditive represented by Chemical Formula 53-1 as a second additive,without a first additive.

Comparative Example 3

A composition for etching was produced by using 99.8 wt % of phosphoricacid (85% aqueous solution) as a first inorganic acid and 0.2 wt % of anadditive represented by Chemical Formula 53-1 as a second additive,without a first additive.

TABLE 1 First inorganic First additive Second additive acid (wt %) (wt%) Example 1 phosphoric dimethyldimethoxy- acid (the silane (1)remaining amount) Example 2 phosphoric diethyldiethoxy- acid (the silane(2) remaining amount) Example 3 phosphoric hexamethyl- acid (thedidisiloxane (0.5) remaining amount) Example 4 phosphoric hexamethyl-acid (the disilazane (1) remaining amount) Example 5 phosphoricdiethyldietoxy- Chemical acid (the silane (1) Formula 53-1 remaining(0.5) amount) Example 6 phosphoric dimethyldimethoxy- Chemical acid (thesilane (1) Formula 53-1 remaining (0.2) amount) Example 7 phosphorichexamethyl- Chemical acid (the disiloxane (0.5) Formula 53-1 remaining(0.5) amount) Example 8 phosphoric hexamethyl- Chemical acid (thedisilazane (1) Formula 53-1 remaining (0.2) amount) Comparativephosphoric Example 1 acid (the remaining amount) Comparative phosphoricChemical Example 2 acid (the Formula 53-1 remaining (0.5) amount)Comparative phosphoric Chemical Example 3 acid (the Formula 53-1remaining (0.2) amount)

Experimental Example 1: Measurement of Selectivity of ProducedCompositions for Etching

Etching of a nitride film and an oxide film at a process temperature of157° C. was performed using the compositions for etching produced in theExamples and Comparative Examples described above, and the etch rate andselectivity for a nitride film and an oxide film were measured using anellipsometer (NANOVIEW, SEMG-1000), which is a thin film thicknessmeasuring apparatus. The etch rates and selectivity values are presentedin Table 2. The etch rate is the value obtained by etching a film for300 seconds and subsequently comparing the film thickness measuredbefore the etching treatment with the film thickness measured after theetching treatment by dividing the difference of the film thicknesses bythe etching time (minutes), while the selectivity represents the ratioof the etch rate for a nitride film with respect to the etch rate for anoxide film.

Meanwhile, in order to simulate an actual high-temperature phosphoricacid process, a preliminary operation of arbitrarily dissolving asilicon nitride film in the compositions for etching produced asdescribed above and increasing the silicon concentration in thesolution, was carried out. At the time of performing the process, as thesilicon nitride film is etched, the silicon concentration in thesolution increases, and thereby, the etch rate of a silicon oxide filmis further decreased. The preliminary operation was carried out untilthe silicon concentration in the solutions reached 50 ppm, 100 ppm, 150ppm, and 200 ppm, respectively, and then the etching was performed. Theresults are presented in Tables 2 and 3 below.

TABLE 2 Silicon Nitride Oxide Process Concen- Etching Etching Nitride/Temperature tration Speed Speed Oxide Film Classification (° C.) (ppm)(Å/min) (Å/min) Selectivity Example 1 157 0 74.58 3.00 24.86 157 5074.02 1.89 39.16 157 100 74.78 1.05 69.31 157 200 69.85 0.53 131.79Example 2 157 0 74.25 3.15 23.57 157 50 73.00 2.01 36.32 157 100 69.251.23 56.30 157 200 68.74 0.64 107.41 Example 3 157 0 74.26 3.10 23.95157 50 73.58 2.15 34.22 157 100 71.26 1.87 38.11 157 200 70.58 0.8781.13 Example 4 157 0 73.83 0.08 23.97 157 50 74.90 2.06 36.36 157 10069.90 1.23 56.83 157 200 67.31 0.45 149.58 Example 5 157 0 68.21 0.28243.61 157 50 67.03 0.13 515.62 157 100 66.58 0.05 1331.60 157 200 65.120.01 6512.00 Example 6 157 0 69.25 0.31 223.39 157 50 67.47 0.13 519.00157 100 65.71 0.06 1095.17 157 200 65.46 0.02 3273.00 Example 7 157 067.89 0.31 226.30 157 50 67.31 0.12 560.92 157 100 65.74 0.07 939.14 157200 63.65 0.01 6365.00 Example 8 157 0 67.90 0.26 261.15 157 50 65.450.11 595.00 157 100 65.03 0.04 1625.75 157 200 64.47 0.01 6447.00

TABLE 3 Silicon Nitride Oxide Nitride/ Process Concen- Etching EtchingOxide Temperature tration Speed Speed Film Classification (° C.) (ppm)(Å/min) (Å/min) Selectivity Comparative 157 0 74.87 3.04 24.63 Example 1157 50 73.54 1.23 59.79 157 100 65.26 0.44 148.32 157 200 63.47 −0.06−1057.83 Comparative 157 0 68.12 0.28 243.29 Example 2 157 50 66.47 0.051329.40 157 100 65.57 −0.01 −6557.00 157 200 64.22 −0.12 −535.17Comparative 157 0 68.03 0.32 212.59 Example 3 157 50 66.73 0.03 2224.33157 100 64.60 −0.02 −3230.00 157 200 62.78 −0.10 −627.80

According to Tables 2 and 3, when comparing the etch selectivity ofExamples 1 to 8 with the first additive and Comparative Examples 1 to 3without the first additive, it can be confirmed that the compositionsfor etching of Examples 1 to 8 show higher etch selectivity for anitride film with respect to an oxide film. In particular, thecompositions for etching of Examples 5 to 8 which also comprised thesecond additive showed higher etch selectivities of 223 to 6512, whichis significantly high.

The present invention is not intended to be limited by the embodimentsdescribed above and the attached drawings, and it will be obvious tothose having ordinary skill in the art to which the present inventionpertains that various replacements, alterations, and modifications canbe made to the extent that the technical idea of the present inventionis maintained.

The present invention relates to a composition for etching,particularly, a high-selectivity composition for etching that canselectively remove a nitride film while minimizing the etch rate of anoxide film, and a method of manufacturing a semiconductor device usingthe same.

Since the composition for etching according to the invention has afeature in that the etch selectivity for a nitride film with respect toan oxide film is high, the EFH can easily be regulated by controllingthe etch rate of an oxide film.

Furthermore, when the composition for etching of the present inventionis employed, damage to the film quality of an oxide film ordeterioration of electrical characteristics caused by etching of anoxide film which occurs at the time of removing a nitride film can beprevented, while particle generation can also be prevented, and thus thedevice characteristics can be improved.

Therefore, the present invention is widely applicable to variousprocesses such as semiconductor production processes where the selectiveremoval of a nitride film with respect to an oxide film is required; adevice separation process for, for example, a flash memory device; aprocess for forming a pipe channel in a 3D flash memory device; and aprocess for forming a diode in a phase change memory, and the presentinvention can improve the process efficiency.

LIST OF REFERENCES

-   -   20, 30, 40: Substrate    -   21: Tunnel oxide film    -   22: Polysilicon film    -   23: Buffer oxide film    -   24: Pad nitride film    -   25: Trench    -   26: Oxide film    -   s 26A: Device separation film    -   31: Pipe gate electrode film    -   32, 35: Nitride film    -   36: Sacrificial film    -   33: First interlayer insulating film    -   34: First gate electrode film    -   37: Second interlayer insulating film    -   38: Second gate electrode film    -   41: Conduction region    -   42: Polysilicon film    -   43: Titanium silicide film    -   44: Titanium nitride film    -   45: Nitride film    -   46: Oxide film

1. A semiconductor element comprising a pipe channel, wherein the pipechannel is formed by a method comprising: forming a pipe gate electrodelayer in which a first nitride layer is buried, forming a cell gatestructure which is an alternating stack structure of an interlayerinsulating layer and a gate electrode layer on the output of the pipegate electrode layer forming process, selectively etching the cell gatestructure to form a second nitride layer buried in a first hole and asecond hole formed exposing the first nitride layer, selectively etchingthe cell gate structure to form a trench separating at least one firstgate electrode layer into portions, forming a selection gate structurecomprising a second interlayer insulating layer and a second gateelectrode layer to form a selection transistor on the output of theselectively etching the cell gate structure to form a trench,selectively etching the selection gate structure to form a third holeand a fourth hole exposing the second nitride layer buried in the firsthole and the second hole, and removing the first nitride layer and thesecond nitride layer under the first nitride layer exposed by the thirdhole and the fourth hole by a wet etching process using a compositionfor etching, wherein the composition for etching comprises: a firstinorganic acid, a first additive represented by Chemical Formula 1, asecond additive comprising a silane inorganic acid salt produced byreaction between a nitric acid and a second silane compound; and asolvent, wherein: the silane compound is a compound selected fromChemical Formulas 10, 20, and their combination, the silane inorganicacid salt is represented by Chemical Formula C260-1.

(In Chemical Formula 1, X is O or N, R1 to R6 are each, independently,selected from the group consisting of hydrogen, a C1-C20 alkyl group, aC1-C20 alkoxy group, a C2-C20 alkenyl group, a C3-C20 cycloalkyl group,a C1-C20 aminoalkyl group, a C6-C20 aryl group, a C1-C20 alkyl carbonylgroup, a C1-C20 alkyl carbonyloxy group, and a C1-C10 cyano alkyl group,and n₁₁ is 0 or 1.)

(In Chemical Formula 10 and Chemical Formula 20, each R¹ to R¹⁰ isindependently selected from a group consisting of hydrogen atom, halogenatom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having1 to 10 carbon atoms, and an aryl group having 6 to 30 carbon atoms, atleast one of R¹ to R⁴ is hydrogen, or an alkoxy group having 1 to 10carbon atoms, and n is one of integer numbers from 1 to 10,)

(In Chemical Formula C260-1, each R¹¹¹ to R¹¹² is independently selectedfrom a group consisting of hydrogen atom, halogen atom, an alkyl grouphaving 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbonatoms, and an aryl group having 6 to 30 carbon atoms, each R¹¹³ to R¹¹⁴is independently hydrogen, n₄ is one of integer numbers from 0 to 2, l₁is one of integer numbers from 0 to 10, m₁ is 0 or 1.)
 2. Thesemiconductor element of claim 1, wherein any one of hydrogen of R¹¹³ toR¹¹⁴ in the Chemical Formula C260-1 is substituted by Chemical FormulaC280-1.

(In Chemical Formula C280-1, any one of R¹³¹ to R¹³² is a couplercoupling to Chemical Formula C260-1, the other is independently selectedfrom a group consisting of hydrogen atom, halogen atom, an alkyl grouphaving 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbonatoms, and an aryl group having 6 to 30 carbon atoms, and each R¹¹³ toR¹¹⁵ is independently hydrogen atom, or substituted by a substituentrepresented by Chemical Formula C280-1, n₄ is one of integer numbersfrom 0 to 2, l₁ is one of integer numbers from 0 to 10, m₁ is 0 or 1.)3. The semiconductor element of claim 1, wherein the silane inorganicacid salt represented by Chemical Formula C260-1 is any one selectedfrom a group consisting of Chemical Formulas 72, 73, 77, 264 and theircombination.

(In Chemical Formulas 72, 73, 77, and 264, each R¹⁻¹, R¹⁻², R¹⁻³, R¹⁻⁴,R²¹, and R²³ is independently selected from a group consisting ofhydrogen atom, halogen atom, an alkyl group having 1 to 10 carbon atoms,an alkoxy group having 1 to 10 carbon atoms, and an aryl group having 6to 30 carbon atoms.)
 4. The semiconductor element of claim 1, whereinthe composition for etching comprises the first additive at a proportionof 0.01% to 15% by weight, the first inorganic acid at a proportion of70% to 99% by weight, the second additive at a proportion of 0.01% to15% by weight, and the solvent as the balance.
 5. A semiconductorelement comprising a pipe channel, wherein the pipe channel is formed bya method comprising: forming a pipe gate electrode layer in which afirst nitride layer is buried, forming a cell gate structure which is analternating stack structure of an interlayer insulating layer and a gateelectrode layer on the output of the pipe gate electrode layer formingprocess, selectively etching the cell gate structure to form a secondnitride layer buried in a first hole and a second hole formed exposingthe first nitride layer, selectively etching the cell gate structure toform a trench separating at least one first gate electrode layer intoportions, forming a selection gate structure comprising a secondinterlayer insulating layer and a second gate electrode layer to form aselection transistor on the output of the selectively etching the cellgate structure to form a trench, selectively etching the selection gatestructure to form a third hole and a fourth hole exposing the secondnitride layer buried in the first hole and the second hole, and removingthe first nitride layer and the second nitride layer under the firstnitride layer exposed by the third hole and the fourth hole by a wetetching process using a composition for etching, wherein the compositionfor etching comprises: a first inorganic acid, a first additiverepresented by Chemical Formula 1, a second additive comprising acompound represented by Chemical Formulas 300, 350, and theircombination, a solvent.

(In Chemical Formula 1, X is O or N, R1 to R6 are each, independently,selected from the group consisting of hydrogen, a C1-C20 alkyl group, aC1-C20 alkoxy group, a C2-C20 alkenyl group, a C3-C20 cycloalkyl group,a C1-C20 aminoalkyl group, a C6-C20 aryl group, a C1-C20 alkyl carbonylgroup, a C1-C20 alkyl carbonyloxy group, and a C1-C10 cyano alkyl group,and n₁₁ is 0 or 1.)

(In Chemical Formula 300, each R² to R⁴ is independently selected from agroup consisting of a hydrogen atom, a halogen atom, a hydroxyl group,an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to10 carbon atoms, an aminoalkyl group having 1 to 10 carbon atoms, anaminoalkoxy group having 1 to 10 carbon atoms, and an aryl group having6 to 30 carbon atoms, and two or three of each R² to R⁴ is independentlya hydroxy group, at least one of R² to R⁴ is an alkoxy group having 1 to10 carbon atoms, an aminoalkyl group having 1 to 10 carbon atoms, anaminoalkoxy group having 1 to 10 carbon atoms.)

(In Chemical Formula 350, each R² to R⁵ is independently selected from agroup consisting of a hydrogen atom, a halogen atom, a hydroxyl group,an alky group having 1 to 10 carbon atoms, an alkoxy group having 1 to10 carbon atoms, an aminoalkyl group having 1 to 10 carbon atoms, anaminoalkoxy group having 1 to 10 carbon atoms, and an aryl group having6 to 30 carbon atoms, at least any one of R² to R⁵ is an alkoxy grouphaving 1 to 10 carbon atoms, an aminoalkyl group having 1 to 10 carbonatoms, or an aminoalkoxy group having 1 to 10 carbon atoms, n is aninteger from 1 to 4.)
 6. The semiconductor element of claim 5, whereinthe composition for etching comprises the first additive at a proportionof 0.01% to 15% by weight, the first inorganic acid at a proportion of70% to 99% by weight, the second additive at a proportion of 0.01% to15% by weight, and the solvent as the balance.